This invention relates to an electric starter interlock for an outboard motor apparatus and particularly for preventing starting with the shift mechanism displaced from neutral.
Outboard motors are widely employed for the propulsion of recreational watercraft or boats and the like. The outboard motor generally includes an internal combustion engine mounted to the upper end of the drive shaft housing and coupled through a suitable drive coupling to a lower propeller unit secured to the bottom of the housing. A pivot bracket assembly secured to the housing is adapted to be pivotally interconnected to the transom of the boat. The drive coupling generally includes a shift mechanism for shifting between neutral, forward and reverse drive position for corresponding propulsion forces. A manually operable shift lever or handle is pivotally mounted to one side of the upper powerhead of the engine and pivoted forwardly and rearwardly for shifting to forward drive and reverse drive position, respectively.
Although many smaller outboards include manually operated rope mechanism, electric starters are also widely employed. Generally, the starter mechanism employs a starting gear secured to the upper end of the engine in combination with a spring-loaded pinion gear carried by a starter shaft. Energizing of the starter drives the pinion gear into starting engagement with the engine starting gear. A very convenient structure provides a push-button actuated switch which, when depressed, closes the starter circuit for engaging of the starting mechanism. The push-button is conveniently mounted directly on the side of the powerhead for manual operation by the operator. Small motors are generally controlled by manual operation of a tiller handle secured to the upper end of the powerhead. The shift control is conventionally a small lever pivotally mounted to the side of the powerhead opposite that of the tiller handle. It is important that the internal combustion engine be started with the drive coupling the neutral position to prevent sudden lurching of the boat, which may result from an attempt to start the engine with the coupling in a drive position.
Various protective devices generally include interlocking switch means connected in the energizing circuit for the electric starter. Alternately, various auxiliary mechanical linkages between the shift mechanism and the starter drive mechanism have also been suggested. For example, in an automotive environment, a flanged floor starter button in combination with a sliding cap which moves beneath such button and is coupled to the gear shift lever is shown in U.S. Pat. No. 1,659,284. In the outboard motor art, a latch member may be generally provided as shown in U.S. Pat. No. 3,782,350 to prevent the pinion from moving into engagement with the starter gear, for example, through a mechanical linkage connected to the shift mechanism. Although the various systems have provided satisfactory interlocks which prevent out-of-neutral starting, the special mechanisms not only contribute to initial cost but may require significant maintenance. The cost factor is of course related to the size and relative cost of the outboard unit. There is therefore a need for simple, reliable and low-cost interlock means which may be economically applied to outboard motors employing powerhead-mounted starter controls.